In conventional methods, severing of such flat materials as veneer sheets is done by vertically shuttling a cutter member while the feed of a veneer sheet to be cut is temporarily stopped. Such conventional methods of severing a veneer sheet are not suitable for continuously operating the preparation of a veneer sheet from a log and severing the veneer sheet in combination, since the cutting operation of a veneer sheet off of a log is in general carried out continuously without stopping. Illustratively stated, in the conventional methods the feed of the veneer sheet must be temporarily stopped at the time of severing. However, the veneer sheet is, in general, continuously fed to the severing stage from the preceding stage of preparation of a veneer sheet from a log. Such continuous operation i.e. preparation of a veneer sheet from a log, can not be combined with the other intermittent operation, i.e. severing of the veneer sheet. Consequently, with the conventional severing methods and device, it is impossible to conduct the whole process for production of sized veneer sheets from a log in a systematic, continuous manner.
Another drawback of the conventional severing device and method is that after the severing operation severed veneer sheets are all fed out to the same place. Therefore, when the device is used for the purpose of removing inferior quality portions detected in a veneer sheet, removed scraps and the veneer sheet of acceptable quality are fed out to the same place and therefore, separation of them is additionally required. Meanwhile, when a veneer sheet is severed into a group of sized veneer sheets of the same length and stacking the thus severed veneer sheets in good trim, the sized veneer sheets need to be fed each by each at a certain interval. In order to automatically obtain such necessary interval of sized veneer sheet-feeding in a conventional method, it is inevitably necessary to prolong the time for cutting or feeding a veneer sheet to be severed, leading to decrease in productivity.
A further drawback of the conventional severing device is that not only the cutter member but also parts connected to it are driven by a power source so that sufficient severing force is available during the severing operation. As a result, there is required a driving means of high power to shuttle the cutter member.
It is therefore an object of the present invention to provide a method of severing a veneer sheet which enables the severing operation without stopping the feed of a veneer sheet for improving efficiency in the manufacture of plywood.
Another object of the present invention is to provide a method as described wherein severed veneer sheets are fed alternately into two different directions.
A further object of the present invention is to provide a method of the character described, wherein a high power drive means for the cutter member is not necessary.
A still further object of the present invention is to provide a device capable of effectively conducting the method as mentioned above.
A still further object of the present invention is to provide a device of the kind described, which is simple in construction and can be manufactured at a reasonable cost.
In one aspect of the present invention, there is provided a method of severing a veneer sheet comprising feeding a veneer sheet using a feeding means including a pair of members adapted to hold a veneer sheet therebetween, said feeding means being continuously driven, sensing an irregularity or a predetermined length of said veneer sheet and actuating a cutter member adapted to pivot in response to a signal from a means for transmitting a signal in accordance with the sensing of the irregularity or the predetermined length of the veneer sheet and to cut the veneer sheet in cooperation with a force by which said veneer sheet is fed, said cutter member being adapted to cut the veneer sheet in each of the pivotal movements of the cutter member which are made alternately in the clockwise and counterclockwise directions.
In another aspect of the present invention, there is provided a device for severing a veneer sheet comprising a veneer sheet feeding means continuously driven and including a pair of members adapted to hold a veneer sheet therebetween, a cutter member pivotally disposed on the feed-out side of the veneer sheet feeding means and having an edge portion adapted to work on the side of the fed-in veneer sheet, a means for sensing an irregularity or a predetermined length of said veneer sheet, a means for transmitting a signal in accordance with the sensing of the irregularity or the predetermined length of the veneer sheet and an actuator for actuating in response to said signal the cutter member to pivot and cut the veneer sheet in cooperation with a force by which the veneer sheet is fed, the severed veneer sheets being adapted to be fed out in two different directions respectively of the upside and downside of the cutter member.
These and other objects, features and advantages of the invention may be readily understood from the following detailed description and appended claims taken in connection with the accompanying drawings.